Li Qiuling, Zhao Yan, Yue Minghui, Xue Yongbiao, Bao Shilai
State Key Laboratory of Molecular and Developmental Biology, Center for Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
State Key Laboratory of Molecular and Developmental Biology, Center for Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Graduate University of the Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100039, China.
J Genet Genomics. 2016 Apr 20;43(4):187-97. doi: 10.1016/j.jgg.2016.02.007. Epub 2016 Mar 14.
Plant root stem cells and their surrounding microenvironment, namely the stem cell niche, are hypersensitive to DNA damage. However, the molecular mechanisms that help maintain the genome stability of root stem cells remain elusive. Here we show that the root stem cells in the skb1 (Shk1 kinase binding protein 1) mutant undergoes DNA damage-induced cell death, which is enhanced when combined with a lesion of the Ataxia-telangiectasia mutated (ATM) or the ATM/RAD3-related (ATR) genes, suggesting that the SKB1 plays a synergistically effect with ATM and ATR in DNA damage pathway. We also provide evidence that SKB1 is required for the maintenance of quiescent center (QC), a root stem cell niche, under DNA damage treatments. Furthermore, we report decreased and ectopic expression of SHORTROOT (SHR) in response to DNA damage in the skb1 root tips, while the expression of SCARECROW (SCR) remains unaffected. Our results uncover a new mechanism of plant root stem cell maintenance under DNA damage conditions that requires SKB1.
植物根尖干细胞及其周围的微环境，即干细胞龛，对DNA损伤高度敏感。然而，有助于维持根尖干细胞基因组稳定性的分子机制仍不清楚。在这里，我们表明skb1（Shk1激酶结合蛋白1）突变体中的根尖干细胞会发生DNA损伤诱导的细胞死亡，当与共济失调毛细血管扩张症突变（ATM）或ATM/ RAD3相关（ATR）基因的损伤相结合时，这种细胞死亡会增强，这表明SKB1在DNA损伤途径中与ATM和ATR发挥协同作用。我们还提供证据表明，在DNA损伤处理下，SKB1是维持静止中心（QC）（一种根尖干细胞龛）所必需的。此外，我们报告称，在skb1根尖中，响应DNA损伤，SHORTROOT（SHR）的表达减少且异位表达，而SCARECROW（SCR）的表达不受影响。我们的结果揭示了一种在DNA损伤条件下植物根尖干细胞维持的新机制，该机制需要SKB1。
